SAT Mc Graw Hill 2011

252 MCGRAW-HILL’S SAT

Lesson 5:Connecting to Knowledge

Know What You Need

Some SAT math questions require you to use special formulas or know the definitions of special terms.

Fortunately, you won’t need to memorize very many formulas (none of that trig stuff, for instance), and

some of the most important ones are given to you right on the test!

Reference Information

Every SAT math section gives you this reference information.Check it out and use it when you need it.

The arc of a circle measures 360°.

Every straight angle measures 180°.

The sum of the measures of the angles in a triangle is 180°.

Memorize the Key Formulas They DON’T

Give You

It’s awfully nice of the SAT to give you those formu-

las, but those are not quite allyou’ll need. Fortu-

nately, we can fit the other key formulas on a single

page. Here they are:

Rate formula (Chapter 9, Lesson 4):

Distance (or work) = rate ×time

Average(arithmetic mean)formulas(Chapter 9

Lesson 2):

Average =

Sum = average ×number of things

Slope formula (Chapter 10, Lesson 4):

Slope =

Midpoint formula (Chapter 10, Lesson 4):

Midpoint =

Percent change formula (Chapter 7, Lesson 5):

Percent change =

final starting

starting

−

× 100 %

xxyy 1212

22

⎛ ++

⎝⎜

⎞

⎠⎟

,

rise

run

yy

xx

=

−

−

21

21

sum

number of things

Memorize the Key Definitions

You’ll also want to memorize the definitions of some

key terms that show up often:

Mode= the number that appears the most fre-

quently in a set. Remember that modeand most

both begin with mo(Chapter 9, Lesson 2).

Median= the “middle number” of a set of

numbers when they are listed in order. If there

are an even number of numbers, the median

is the average of the twomiddle numbers

(Chapter 9, Lesson 2).

Remainder= the whole numberleft over when

one whole numberhas been divided into an-

other whole numbera whole numberof times

(Chapter 7, Lesson 7).

Absolute value= the distance a number is from

0 on the number line (Chapter 8, Lesson 6).

Prime number= an integer greater than 1 that

is divisible onlyby itself and 1 (Chapter 7,

Lesson 7).

Factor= a number or expression that is part of a

product.(Product= result of a multiplication.)

r

A = πr^2

C = 2 πr

w

A = 
w A =^1 / 2 bh V = 
wh V = πr^2 h c^2 = a^2 + b^2 Special right triangles

h

b 

w

h

r

h b

c

a

2 x

x

xs

s

3 s

2

30 °

60 °

45 °

45 °